Fungal growth on an old book, due to high levels of relative
humidity. The book is part of the Historic Archive of the
city of La Laguna, on Tenerife Island, Spain, one of the sites
where the GCI is testing methods to control relative humidity.
Photo: Shin Maekawa.

The main facade of Hollybourne Cottage in the historic district
of Jekyll Island in Georgia, U.S.A. Here, the GCI is testing
a humidistatically controlled mechanical ventilation and electrical
heating system for its efficacy in controlling the high relative
humidity problem in the building. Photo: Shin Maekawa.

Extended wood decay of interior sheathings and floors on
the ground floor of Hollybourne Cottage. The biodeterioration
of building fabrics is the result of high levels of relative
humidity in the cottage's walls and basement. Photo: Shin
Maekawa.

One of supply fans for the ventilation system being installed
in the Hollybourne Cottage's basement. Photo: Franciza Toledo.

An inside view of the cottage's attic, with exhaust fans
mounted on the window openings. External louvers provide protection
on the outside. Photo: Franciza Toledo.

The main facade of the Archivo del Ayuntamiento de La Lagunathe
Historic Archive of the city of La Lagunaon Tenerife
Island, Spain. Here, as at Hollybourne Cottage, the GCI is
experimenting with systems to moderate the high relative-humidity
problem in the building. Photo: Shin Maekawa.

An inside view of the Historic Archive, with the monitoring
sensors in the foreground and an exhaust fan, mounted on the
window, in the background. Photo: Shin Maekawa.

View of the Historic Archive, with a convective heater and
agitator fan in place. Photo: Shin Maekawa.